Gear shaping machine



May 16, 1950 G. G. FREDERlcHs GEAR SHAPING MACHINE original Filed Mays, 1941 Patented May 16, 1950 UNITED STATES PATENT OFFICE GEAR SHAPING MACHINE Georg Gert Frederichs, Kassel-Brasselsberg, Germany; vested in the Attorney General of the United States many December 12, 1939 6 Claims.

My invention relates to machines for shaping gears by the conjoint relative reciprocation and rotation of the work piece and the tool, in which machines the tool is on its return stroke disengaged from the work piece. This application is a division of copending application Serial No. 392,532, led May 8, 1941, new Patent No. 2,364,065, granted ADecember 5, 1944.

In the known machines of the said class either the tool spindle together with the cutter and the spindle carrier or the rwhole work supporting table together ywith the work piece must be withdrawn, and by the short and rapid movements of the heavy spindle carrier or of the supporting table the machinery is subjected to violent shocks which have an unfavourable inluence on the cleanliness and exactness of the work. Moreover bulky driving means are necessary for the said movements, which means are highly subjected to wear and require much power. It is especially diicult to x the heavy supporting table at each shaping stroke.

The object of my invention is to eliminate the said drawbacks by disengaging the tool from the work piece in such a way that the cutter is moved relatively to the tool spindle, or that the tool spindle together with the cutter is moved relatively to the spindle carrier. By this arrangement it is rendered possible to use two cutting tools, of which the one performs the rough-cutting, whereas the other performs the smoothing. In this way a greater cleanliness and exact-ness of the toothed -work and a longer duration of the cutting edges of the tools are attained.

Other objects of my invention will be apparent 'from the following specification referring to the drawings. According to a preferred embodiment of my invention the movement of the cutter relatively to the tool spindle is executed with hydraulic means, and an object oi my invention is also the exact adjustment of the tool relatively to the work piece.

In the drawings several embodiments oi my invention are shown.

Fig. 1 is a side elevation of the gear shaping machine, partly in section;

Fig. 2 is a section through a portion of the tool spindle according to which the cutter is displaced by an eccentric bolt;

Fig. 3 is a section through the tool spindle according to the line 3-3 of Fig. 2;

Fig. 4 is a section according to the line 4--4 oi.' Fig. 2;

Fig. 5 shows an embodiment according to `which the cutter is moved relatively to the tool spindle both in the axial and radial direction by means of hydraulically actuated pistons, and

Fig. `6 is a section according to the line 6 5 of Fig. 5.

The work piece l is framed on the table 2 which is rigidly connected with the spindle carrier 3 in which the tool spindle i is guided in vertical and axial direction. The tool spindle has several annular rack-teeth meshing with a toothed sector 'l which is rotatable about the axis 6. By a rotation of the said sector the tool spindle is forced upwards or downwards in a vertical direction. Simultaneously the work piece i as well as the tool spindle 4 is rotated. The rotation of the tool spindle is executed by means of the worm 8 and the yworm wheel 9. The cutter 2U is articulated to the tool spindle 4.

According to the modication shown in Figs. 2, 3 and 4, the tool retains its horizontal position during its movements relatively to the tool spindle. The tool spindle 4 has a spur cogging I8 which is engaged by a corresponding countercogging of the disc i9 for the cutter 2o. Inside of the spindle 4 a cylinder 33 is rotatable. The said cylinder has an eccentric bore in which a bolt 34 is rotatable and axially displaceable. The said bolt 34 is threaded at 35 and has an eccentrically arranged cylindrical stud 36 which is concentric to the spindle s and which engages with a concentric bore of the disc i9. The disc is held on the stud `at one end of the same by the annular shoulder 31 and at the other end by a nut 38 which engages the disc through the intermediary of a ball bearing 39.

The upper end of the bolt 34 has a slot in which a slide member 4l) is inserted the end faces oi' which are adjacent the walls of a cylindrical chamber 4| 42 in the socket 33. The member 40 forms a hydraulic rotatable piston which imparts rotation to the bolt 34. Through the slide member the cylindrical chamber is divided into the parts 4l and 42.

The channels 43, 44, 45 and 46 form the inlets to the pressure chambers 4 l, 42.

The cylinder 33 has a central pivot fil which protrudes through a corresponding bore of the tool spindle 4 to the outside. To the said pivot, a lever 48 is keyed which holds the cylinder during the operation in such a way that the tool spindle 4 rotates about the cylinder. In this 'way the device for radially displacing the cutter remains immovable.

The operation is as follows: The pressure liquid enters the chamber 42 and turns the slidemember 40 and with it the bolt 34. Through the engender a tilting movement of the cutter and thefcutter moves downwards.

idle-4 moves upwards.

ychamber I l through the channel i6.

vits initial lposition. rposition to'execute another working stroke.

intermediary of the threads 35 the bolt 365 is screwed downwards. Simultaneously the eccentric stud Sii oscillates about the axis of the bolt 34, andin consequence thereof the disc i9 together withthe cutter 25 is cleared away from the cogging is ofthe tool spindle li. But simultaneously the cutter is also cleared away in radial direction from the work piece l, so that the return stroke of the tool can takeplace unimpeded by the work piece.

Now the pressure liquid is fed through the channels @13, M to the chamber di. The slide member 4% and the bolt 34 are now rotated in the opposite direction. nconseduence thereof the bolt 34 moves upwards, and the disc -ll `is brought into engagement with the spur-cogging I8 oi the tool spindle 4. The cutter is now in position to execute the next following 'working stroke.

The Figs. 5 and 6 show a construction wherein thepressure-liquid influences a-piston i3 which axially displaces the bolt This bolt does not but displaces the same in the axial direction parallel to itself. rl'he radial displacement of the cutter is here engendered by the piston which is lguided in the bore 5t into which the pressure liquid is fed through the channel 5i. The-channel 5i, the bore and the piston are-providedinthe bolt 52 which centrically and rotatablyrmounted in the bolt i2.

The operationisas follows: The pressure liquid isied-tothe chamber M through the channel lil. The pistontogether with the bolt the disc Simultanecusly the'pressure liquid is pressed 'through the channel 5l into the chamber The disc and the cutter which are clear yfrom the cogn ging are now radially moved away from the work piece i by thepiston 149. Now also the tool spin- In the uppermostposition of the spindle the pressure liquid is fed to -the The `piston i3 and :the cutter move upwards, and the disons-again brought into engagement with the cogging iii in such a way ythat the disc is centrically adjusted relatively to theaxis oi the tool spindle. Thereby the piston i9 also returns into The cutter is now in the What Ibla-im and ydesire to secure by Letters `Patent is:

l. A gear shaping machine comprising a tool spindle, a gear shaper-cutter held by the spindle, a table carrying the gear blank, means `for engendering a conjoint lrelative reciproca- -tionand rotationof the gear blankand the cutter, acylindrical stud about which the cutter is rotatable and a threaded bolt eccentrically and rigidly connected with the said stud and eccentrically guided in the tool spindle.

2. A gear shaping machine `comprising a tool spindle, a gear Shaper cutter held bythe said spindle, a table carrying the gear blank, means for engendering a conjoint relative reciprocation `and rotation of the gear blank and the cutter,

a cylindrical stud about which the cutter is rotatable, a threaded and slotted bolt eccentrically and rigidly connected with the said stud and eccentrically guided in the tool spindle and a slide member engaging the slot of the bolt and forming a rotatable hydraulic piston for imparting rotary motion to the bolt.

3. A gear shaping machine comprising a tool spindle, a gear Shaper cutter held by the said spindle, a table carrying the gear blank, means for engendering a conjoint relative reciprocation and rotation of the gear blank and the cutter, @a cylindrical stud about which the cutter is rotatable, a threaded and slotted bolt eccentrically and rigidly connected with the said stud and eccentrically guided in the tool spindle, a slide member engaging the slot oi the bolt and forming a rotatable hydraulic piston for impartingr rotary motion to the bolt, a socket guiding the bolt and rotatably mounted in the tool spindle, and a lever for rotating the-socket.

ll. Agear shaping machine comprising a tool spindle having a spur cogging, a gear Shaper cutter having also a spur ccgging engaging the spur'cogging ofthe spindle during the working, means for engendering a conjoint relative rcciprocation and rotation oi the gear blank and the cutter and means for displacing the cutter relatively to'the axis of the-spindle at the return stroke of the cutter, such displacing means consistingoi a hydraulic member for clearing the cutter away from the tool spindle and-of a hydraulic member for subsequently displacing the cutter relatively to the axis of the tool spindle.

5. in a shaping -maehine for forming teeth upon a work piece, the combination ci an elongated spindle member rotatably mounted upon said cylindrical member, a circular gear cutter member substantially axially aligned with said spindle member, said two last-named members having interengageable coggings on 'their proximate laces, means radially movable with respect tothe cylindrical member-arid engageable with the cutter member, and hydraulic means Afor operating said radially movable means to effect displacement-oi the cutter member-radially oi the cylindrical member.

6. A gear shaping machine according to claim 5 wherein said hydraulic means comprises iluid conduits formed respectively in the cylindrical and spindle `members and communicating one with another.

GEORG GERT FREDERICHS.

REFERENCES CITED The following-references are of record inthe rile of this patent:

'UNITED STATES PATENTS Number Name Date 2,055,132 McLeod Sept. 22, 1936 2,364,065 Frederichs Dec. 5, 1944 FOREIGN PATENTS Number Country Date 432,475 Great Britain July 26, 1935 

